I have recently bought a James Captain 20L with an AMC 20T engine in. I thought the engine just needed bringing back to life, however when i got the bike home i realised it was a lot more work! As it had nipped all three rings and a big chunk missing between the rings.

I have spoken to a friend of mine who used to race Villiers 210 karts and we came to the conclusion that if we could get spares such as conrods we will do a convesion or put an ali cylinder on with a Villiers piston and head. Unfortunatly, this isnt as easy as we descussed as i can not find any sort of spares for this engine!

I hope there is someone out there that has any thoughts on what i could do its a 6" (152mm) conrod that i need with a 1inch (26mm) crank pin. If there is something maufactured similar to this please could you let me know.

Are you aware the 20T transfer ports are groves in the barrel? The big end and crank pin are not strong and sometimes move.They are not as bad as made out to be but I don't think they will stand much tuning.Regards Ken

Simon Batman of Nametab used to rebuild the cranks but I think he sold up. The best place to find spares is Ebay. Cases and part engines come up often. How does the Bore and stroke compare to the Villiers?Ken

Both the Villiers and AMC 20T share the same bore and stroke, so a Villiers piston /barrel will work on a 20T engine, but the barrel lengths are different, so spacers need to be made up to accommodate the different stud spacings and the rod length, as long as the piston is in the correct position at top of stroke, port timing will correct itself, placing a different conrod into the AMC crank will be an altogether more complicated system.I have owned 2 AMC trials bikes fitted with Villiers/Greeves square barrels, these were both 250cc bikes and both required a spacer under the cylinder, both used the standard crankshaft and rod for the AMC 250

If converting the AMC 20T to Villiers top end, you have 2 different Barrel lengths to consider, the longer 6/7/8E cylinder or the shorter 9/10E cylinder, but as long as the distance from the crankcase, base gasket surface to the top of the AMC 20T cylinder can be replicated with the Villiers barrel and a Villiers 197cc piston used it will work OK

kerabo wrote:Simon Batman of Nametab used to rebuild the cranks but I think he sold up. The best place to find spares is Ebay. Cases and part engines come up often. How does the Bore and stroke compare to the Villiers?Ken

Yes Simon is now just doing the engineering work, engine rebuilds, cylinder boring, crankshaft repair etc and an excellent job he does too !He has sold his spares supply business to Villiers services, but not the engineering services